Having been the one that was cheated on I guess I'll chime in.
I did grow to have compersion for Cricket. What fell apart for us was a huge difference in personality and approaches to life, no that she was the other woman. But that took a lot of time and a lot of work.
Karma decided for me what I could handle and what I couldn't, what I would be okay with and what I wouldn't. It would have saved a lot of pain, a lot tears, a lot of self doubt and doubt in him had he simply said " Your illness is getting in the way of some of my needs. I know this is not your fault, but I need to find it elsewhere or I will end up cheating and hurting you." Things would have gone a hell of a lot differently.
Instead he went from having a relationship with Cricket to having to be babysat. In order for me to feel safe and secure I needed to know they could be trusted. So they dated under surpervision for quite some time and unless they lied about that too, they didn't have sex again from the time I found out to the time they broke up. At first because of me and then later for other reasons. But the point is, by cheating and coming clean later you are forcing a lot of things you may not have considered. Will you be ready to go through the hell it takes to regain the trust you broke? Are you willing to throw the entire relationship away because cheating is something they won't tolerate? In which case I think you should end it now.
Either out of strength or stupidity, depending on who you talk to, I didn't leave Karma and we've worked hard to fix our marriage. Yes we did make it through, but it took a lot of work, a lot of saccrifice and Karma lost all privacy for a long while.
I don't think this is a matter of confines of religious or social matters. I think it is a matter of you rationalizing to get what you want. You are making decisions for people without including them, that is cruel and unfair. who are you to decide what can or cannot be handled by someone else? You are risking their health and well being by cheating.
And I think BU hit it dead on-it seems to stem from a fear that you cannot handle how they will react, not that they are not ready.
Karma made his own life hell by deciding for me, when in reality had he been honest from the beging, things would have gone a lot smoother.
When I found out, that breech of trust and respect cut me to the core. I had already contacted my lawyer and my family to arrange moving and divorce. For some reason I chose to stay and we are stronger than ever. But not everyone is willing to do that. And I cannot begin to put into words the harm it caused. I really questioned why we were married at all if he found me to be so unable to handle this. If he had so little respect for me to include me in decisions that affected my life as well as his. It wasn't just trust we had to rebuild, it was the entire marriage. It wasn't just other women I doubted him on, it was every word out of his mouth. I didn't know if I could trust anything he said to me.
We gave our marriage a year, and in may we celebrated the choice to not divorce. But it was one hell of a year and we still aren't completely healed. I still have moments where I question his honesty.
You're asking a lot of everyone involved if you proceed with this and for at least one person, they don't even know the stakes.
As I said, coming from the one who was cheated on, the choice to cheat instead of being honest is disrespectful, cruel and cowardly. I'd take a long hard look at my relationship and decided if it is really worth putting someone I claim to love and respect, through some of the worst emotional trauma out there. Because it's not just trust in you that is lost, it's value in self as well. Has Karma been honest from the begining I would know why he was looking elsewhere. But instead I was left to question everything about myself and to doubt every word of reassurance.